Four motor paradigms have been designed to gain quantitative and graphic data on upper extremity movement in the monkey. The study is designed to elucidate the functional capacity of the sensorimotor cortex and the subcortical path-ways of the brainstem that enable a primate to move when this cortex has been destroyed. One of the paradigms will behaviorally test the concept that specific polysensory convergent areas of the cortex are important to an integrative mechanism that may control motor output in response to external stimuli. It is anticipated that a difficult paradigm will determine the role of the sensorimotor cortex in the on line modification of movement.